Boeing Lightweight Tank Tests Open Way To Broader Aerospace Roles
Boeing says successful tests of an all-composite cryogenic fuel tank at NASA Marshall Space Flight Center clear the way for large-scale application of the lightweight technology in future spacecraft and aircraft.
The 14-ft.-dia. tank underwent multiple test cycles during the evaluation, including a final structural test which it survived despite pressures 3.75 times the design requirement. Boeing says payload mass could be increased by up to 30% if the composite tank is used in place of the conventional aluminum-lithium structure for future versions of the Exploration Upper Stage in NASA’s Space Launch System.
Releasing first details of the test, which passed the final critical structural evaluation in late 2021, Boeing adds the technology will also be suitable for potential use in future liquid hydrogen-fueled aircraft.
The tests at Marshall build on several earlier generation tank projects, including work in the 2010s for DARPA’s XSP (Experimental Spaceplane) program under which Boeing built and tested cryogenic carbon composite liquid oxygen and liquid hydrogen tanks. Although Boeing withdrew in early 2020 from the XSP—a vertical launch and horizontal landing vehicle designed to demonstrate the feasibility of boosting payloads into space with an aircraft-like operational tempo—key lessons were learned during tank development.
The baseline construction methods for the cryogenic tank are based on advanced robotic fiber placement techniques honed by Boeing during development of the 787 commercial airliner, and through the Composite Cryotank Technologies and Demonstration (CCTD) project with NASA. The CCTD program focused on proof-of-concept tanks 7.9 ft. and 18 ft. in diameter, while the XSP pressure vessels were around 13 ft. in diameter and longer than either of the NASA sample structures.